Hammer-drill



W. T. AYER.

HAMMER DRILL.

APPLICATION FILED MAR. a. 1917.

136,47. Patented Feb. 15, 1921.

Y'zi a vwewfoz ZWM UNITED STATES PATENT OFFICE.

WILLIAM T. AYEB, 0] DOVER, NEW JERSEY, ASSIGNOR TficKIERNAN-TERRY DRILL COMPANY, 0] DOVER, NEW JERSEY, A COBPORATIQN OF NEW JERSEY.

HAMMER-DRILL.

Application filed March 3,

To all whom it may concern:

Be it known that I, lVILLiAM T. AYER, a citizen of the United States of America, and a resident of Dover, Morris county, and State of New Jersey, have invented certain new and useful Improvements in Hammer- Drills, of which the following is a specification, reference being had to the accompanyin drawings, forming a part thereof.

y invention relates to power actuated drills and has special reference to such as are adapted for rock drilling and are known as hammer drills.

One object of my invention is to provide a simple and compact device of the aforesaid character that shall be adapted to operate at high speed.

Anotherobject is to provide a compact valve member or chest which may, if desired, be removably attached to the cylinder of the drill and which shall include a particularly light and effective distributing valve, and a throttle valve which is adapted to control the supply of motive fluid not only to the motor but also to the hollow drill steel.

In order that my invention may be thoroughly understood I will now proceed to describe the same in the following specification, and then point out the novel features thereof in appended claims.

Referring to the drawings:

Figure 1 is a longitudinal section of a hammer drill arranged and constructed in accordance with my invention and constitut-- ing an embodiment thereof.

Figs. 2 and 3 are sectional details drawn to a larger scale, showing particularly the valve member with the distributing valve in its respective positions.

Fig. 4 shows the throttle valve adjusted to blow motive fluid through the drill steel without supplying it to the motor. Fig. 5 is a detail view of the distributing valve.

In the structure illustrated, 1O designates the cylinder, 11 the rear head, 12 the piston and 13 the rifle bar which produces a rotative movement of the piston as it reciprocates in the cylinder. 14 is a valve block or chest which is secured to the cylinder by bolts 15; 16 is the front cylinder head, and 17 the socket which is adapted to receix e a drill steel 18. l

The piston 12 has a hammer projection 19 which is fluted as shown at 20 and co- Speciflcation of Letters Patent.

Patented Feb. 15, 1921.

1917. Serial No. 152,189.

operates with grooves 21 in the socket 17, the arrangement of parts being such that the socket 17 turns with the piston in a well known manner. I

The drill steel 18 is provided with a longitudinal passage 22 and constitutes a well known form of hollow drill steel.

The cylinder 10 is provided with exhaust ports 24 and 25, and inlet ports 26 and 27. The exhaust ports open to the atmosphere through passage 28 and the inlet ports communicate with the valve chest as hereinafter explained.

The valve chest 14 has a longitudinal recess forming .a valve chamber 29 in which a distributing valve 30 is disposed. It also has a transverse, preferably tapered, valve socket 31 into which a hollow valve plug 32 is fitted. Motive fluid is admitted to the interior chamber 32 of the throttle valve plug 32, and flows through a passage 33 to an annular groove 34 in the valvechamber 29.

A passage 35 connects the inlet port 27 in the cylinder with the throttle valve socket 31. A passage 36 of th valve chest in conjunction with a passagi 37 of the cylinder is adapted to establish a connection from the throttle valve socket to the drill socket chamber 38 with which the passage in the drill steel communicates.

The throttle valve has a port 40 which is adapted to establish communication from the interior supply source to the passage 33, and it has a circumferential passage 41 adapted to establish communication between the passages 35 and 36 as shown in Figs. 2 and 3.

It also has a port 42 which is adapted to establish communication from the interior supply source to the port 36 when the valve is in one of its positions to close the passages 33 and 35 as shown in Fig. 4.

The distributing valve 30 is particularly small and light in order that it may operate at high speed and has the form of a short cylindrical block with sphericallycurved recesses 44 and 45 at its ends and an annular groove 46 at an intermediate point in its length as clearly shown in Fig. 5. It also has ports 47 and 48 connecting the annular groove 46 with the respective recesses 44 and 45.

The operation of the device is as follows :--Assuming that the distributing valve i and the throttle valve occupy-the positions as shown in Fig. 1, motive fluid is then admitted from the valve chamber 32 to port 40, passage 33, ports 47 of the distributing valve, and passage 26 to therear end of the cylinder. Thus motive fluid acts upon the piston 12 and produces a workin stroke for the hammer.

hen the piston has advanced sufficiently to uncover the port 24 the motive fluid 1s exhausted and the pressure in the chamber provided by the recess 44is sufliciently lowered to permit the distributlng valve to be thrown to its opposite pos1t1on by the pressure in the chamber 45 which is admitted through ports 48. In other words, the valve is moved from the position of Fig. 2 to the position of Fig. 3. Motive fluid now flows from the recess chamber 45 through passage 27 to the lower end of the cylinder and lifts the hammer. During this stroke motive fluid is also supplied however, through passages 35, 41, 36 and 37 to the socket chamber 38 and is blown through the drill steel. I

Thus the entire motive fluid pressure is utilized on the working stroke of the hammer and on the return stroke a part of the vmotive fluidl is diverted through the drill steel for cleaning away the cuttings in a well known manner.

The intermittent blowing of fluid through the steel is particularly effective in removing the cuttings and furthermore, if it is desired to blow out the drill steel before the motor is started, the throttle valve may be thrown into the position shown in Fig. 4 in which motive fluid is supplied directly through port 42 and passages 36 and 3 through the drill steel while the passage to the distributing valve is closed.

What I claim is:

1. A hammer drill comprising a cylinder, a piston, a hollow drill steel, a distributing valve, a connection from one end of the distributing valve to the drill steel and a throttle valve for controlling the flow of motive fluid to the distributing valve and arranged to control said connection.

2. A hammer drill comprising a cylinder, a valve chest having a distributing valve chamber communicating through inlet passages to the respective ends of the cylinder, a distributing valve for alternately opening sages to the respective ends of the cylinder,

a distributing valve for alternately opening.

and closing the inlet passages, and a throttle valve adapted in one position to establish a motive fluid connection to the distributing valve and to a branch connection from one of the inlet passages to the hollow drill steel and 1n another positionto establish a direct motive fluid connection from the throttle to the hollow drill steel independently of the cylinder. 7

4. A ham-mer drill comprising a cylinder, a valve chest having a distributin valve chamber communicating through in ct passages to the respective ends of the cylinder, a distributing valve for alternately opening and closing the inlet passages, and a throttle valve for controlling the flow of motive fluid to the distributing valve and arranged to establish a branch connection from; the return stroke inlet passage through the drillsteel, whereby a portion of the motive fluid is blown through the drill steel during each return stroke of the hammer.

5. A hammer drill comprising a cylinder, a piston, a valve chest attached to the cylinder, a valve having a distributin valve chamber communicating through t e. inlet passages to the respective ends of the cylinder, a distributing valve for alternatelyopening and closing the passages, and a throttle valve adjacent to the distributing valve in the valve chest, a blow-out passage to the throttle valve, said throttleivalve having a passage arranged to open communication with the distributing valve, another passage arranged to connect one of the inlet passages with the blow-out passage and a third passage arranged to be connected directly with the blow out passage.

In witness whereof, I have hereunto set my hand this first day of March, 1917.

WILLIAM T. AYER.

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